Preparation and anti-biofouling performance of PSf/TiO₂ ultrafiltration membrane by in-situ embedment approach

The in-situ embedment approach was adopted to surface-modify polysulfone ultrafiltration membranes using TiO₂ nanoparticles. The coverage ratio of nanoparticles on membranes surface was changed by varying the pH and TiO₂ nanoparticle concentration in the water (coagulation) bath. The membranes were characterized and evaluated by scanning electron microscope observation, contact angle measurement and conducting anti-biofouling test using P. aeruginosa. The results show that the well-dispersed TiO₂ nanoparticles in the water bath of pH 4 were successfully embedded onto the membrane surface with the coverage ratio being variable. A membrane was more hydrophilic when the TiO₂ coverage ratio was higher. Compared with the unmodified membrane, the modified membrane had a similar filterability and a higher anti-biofouling ability. The anti-biofouling ability was dependent on the TiO₂ coverage ratio. The best anti-biofouling performance was achieved when the coverage ratio was between 22.4% and 27.7%, for which the P. aeruginosa adhesion (after 12-hour cultivation) reduced by 90% and the biofilm thickness (after 24-hour cultivation) decreased by 70%.